Crystalline And Amorphous Metallic Membranes For Hydrogen .

Crystalline and Amorphous Metallic Membranes for Hydrogen SeparationbyTianmiao LaiA Dissertation Presented in Partial Fulfillmentof the Requirements for the DegreeDoctor of PhilosophyApproved August 2015 by theGraduate Supervisory Committee:Mary Laura Lind, ChairJerry LinJian LiARIZONA STATE UNIVERSITYDecember 2015

ABSTRACTIn the United States, 95% of the industrially produced hydrogen is from naturalgas reforming. Membrane-based techniques offer great potential for energy efficienthydrogen separations. Pd77Ag23 is the bench-mark metallic membrane material forhydrogen separation at high temperatures. However, the high cost of palladium limitswidespread application. Amorphous metals with lower cost elements are one alternativeto replace palladium-based membranes. The overall aim of this thesis is to investigate thepotential of binary and ternary amorphous metallic membranes for hydrogen separation.First, as a benchmark, the influence of surface state of Pd77Ag23 crystalline metallicmembranes on the hydrogen permeability was investigated. Second, the hydrogenpermeability, thermal stability and mechanical properties of Cu-Zr and Ni60Nb35M5(M Sn, Ti and Zr) amorphous metallic membranes was evaluated.Different heat treatments were applied to commercial Pd77Ag23 membranes topromote surface segregation. X-ray photoelectron spectroscopy (XPS) analysis indicatesthat the membrane surface composition changed after heat treatment. The surface area ofall membranes increased after heat treatment. The higher the surface Pd/(Pd Ag) ratio,the higher the hydrogen permeability. Surface carbon removal and surface area increasecannot explain the observed permeability differences.Previous computational modeling predicted that Cu54Zr46 would have highhydrogen permeability. Amorphous metallic Cu-Zr (Zr 37, 54, 60 at. %) membraneswere synthesized and investigated. The surface oxides may result in the lowerexperimental hydrogen permeability lower than that predicted by the simulations. Thepermeability decrease indicates that the Cu-Zr alloys crystallized in less than two hoursi

during the test (performed at 300 C) at temperatures below the glass transitiontemperature. This original experimental results show that thermal stability of amorphousmetallic membranes is critical for hydrogen separation applications.The hydrogen permeability of Ni60Nb35M5 (M Sn, Ti and Zr) amorphousmetallic membranes was investigated. Nanoindentation shows that the Young’s modulusand hardness increased after hydrogen permeability test. The structure is maintainedamorphous after 24 hours of hydrogen permeability testing at 400 C. The maximumhydrogen permeability of three alloys is 10-10 mol m-1 s-1 Pa-0.5. Though these alloysexhibited a slight hydrogen permeability decreased during the test, the amorphousmetallic membranes were thermally stable and did not crystalize.ii

DEDICATIONTo my parents and grandfatheriii

ACKNOWLEDGMENTSFirst and foremost, I would like to express my deepest appreciation to my advisor,Dr. Mary Laura Lind. It has been an honor for me to be her first Ph.D. student. She gaveme the opportunity to do exciting and interesting research in several different projects. Iwant to thank her for all his continuous support, guidance, assistance and encouragementduring my pursuit of Ph.D. I have been motivated by the joy, curiosity and enthusiasmshe has for her research.I would like to thank Dr. Lin and Dr. Li for their willingness to serve on mycommittee. I really appreciate them for taking the time and efforts to make invaluableinputs and suggestions to my research and dissertation. I would also like to thank FredPena for his assistance in building set up, equipment repair and maintenance in the lab.I would like to thank the help of my collaborators who helped me enormouslywith my research. They are: Prof. Jerry Lin’s group for the help of hydrogen permeabilitytest system setup; Prof. William L. Johnson’s group in Caltech, George Kaltenboch,Andrew Hoff; Prof. Zhifeng Ren’s group in University of Houston; Prof. WilliamPetuskey's group; Dr. Rongshun Zhu and Prof. David Sholl in Georgia Institute ofTechnology. I would also like to thank current and former group members.I highly appreciate Ira A. Fulton Schools of Engineering, ASU; AmericanChemical Society Petroleum Research Funding DNI (Award #52461-DNI10) for thefinancial support of this work. We gratefully acknowledge the use of facilities with theLeRoy- Eyring Center for Solid State Science at Arizona State University.iv

TABLE OF CONTENTSPageLIST OF TABLES . ixLIST OF FIGURES . xiCHAPTER1GENERAL INTRODUCTION .11.1 Introduction .11.2 Polymeric Membranes .41.3 Inorganic Membranes .71.3.1 Non-Metallic Inorganic Membranes .81.3.2 Pd-Based and Other Crystalline Dense Metallic Membranes.101.3.2.1 Pd-Based Membranes .111.3.2.2 Non-Pd-Based Crystalline Membranes.161.4 Amorphous Metals .181.4.1 Structural, Thermal and Mechanical Properties.201.4.2 Amorphous Metallic Membranes for Hydrogen Separation .241.5 Research Objectives and Significance .311.6 Structure of Chapters .322 THE EFFECT OF SURFACE STATE ON THE HYDROGEN PERMEABILITY OFPD77AG23 CRYSTALLINE METALLIC MEMBRANES .342.1 Introduction .342.2 Experimental .362.2.1 Materials .36v

CHAPTERPage2.2.2 Characterizations.382.2.2.1 Surface Composition .382.2.2.2 Surface Morphology and Roughness .392.2.2.3 Hydrogen Permeability Measurement .392.3 Results and Discussions .442.3.1 Surface Composition and Elemental Binding Energy .442.3.2 Surface Roughness and Morphology .512.3.3 Hydrogen Permeability Test .552.4 Conclusions .633HYDROGEN PERMEABILITY OF CU-ZR AMORPHOUS METALLICMEMBRANES AND STABILITY .653.1 Introduction .653.2 Experimental .673.2.1 Materials .673.2.2 Membrane Synthesis .703.2.3 Characterizations.743.2.3.1 Structure .743.2.3.2 Surface Depth Profile .753.2.3.3 Thermal Properties .753.2.3.4 Hydrogen Permeability Test .753.3 Results and Discussions .773.3.1 Structure and Thermal Properties .77vi

CHAPTERPage3.3.2 Hydrogen Permeability of Pd-Coated and Uncoated Samples .803.3.3 Surface Oxidization and Thermal Stability.813.4 Conclusions .854 HYDROGEN PERMEABILITY OF NI-NB-X (X SN, TI AND ZR) AMORPHOUSMETALLIC MEMBRANES AND MECHANICAL PROPERTIES CHANGE BYHYDROGEN .874.1 Introduction .874.2 Experiments .894.2.1 Materials .894.2.2 Membrane Synthesis .904.2.3 Characterizations.904.2.3.1 Structures .904.2.3.2 Thermal Properties .914.2.3.3 Nanoindentation .914.2.3.4 Hydrogen Permeability Test .934.3 Results and Discussions .934.3.1 Structure and Thermal Properties .934.3.2 Mechanical Properties Before and After Hydrogen Permeation Test .964.3.3 Hydrogen Permeability and Thermal Stability .1004.4 Conclusions .1035 SUMMARY AND RECOMMENDATIONS.104vii

CHAPTERPageREFERENCES .107APPENDIXABASIC DEFINITIONS AND UNIT AND ERROR PROPAGATION.124BPARTS OF THE HYDROGEN PERMEATION SYSTEM.127CDESIGN OF STAINLESS STEEL MODULE TO SEAL THE SELF-SUPPORTEDMETALLIC MEMBRANES .129DMODIFICATION OF THE HYDROGEN PERMEATION SYSTEM WITHTHERMOCOUPLE INSIDE THE STAINLESS STEEL CELL.134EPERMEABILITY DATA OF PD77AG23 SAMPLES .137FPERMEABILITY DATA OF AMORPHOUS CU-ZR SAMPLES .142GPERMEABILITY DATA OF AMORPHOUS NINB-BASED MEMBRANES .148viii

LIST OF TABLESTablePage1.1 Comparison of Different Types of Hydrogen Separation Methods Reproduced from(Ho and Sirkar 1992) .31.2 Permeability and Separation Factors for Polymeric Membranes .72.1 Details of Different Heat Treatments. .372.2 Binding Energy of Pd 3d5/2 and Ag 3d5/2 After Heat Treatment and After HydrogenPermeation Test .482.3 Roughness and Surface Area Difference After Heat Treatment and Permeation Test .522.4 Permeability Raw Data of a Sample A (As-Received Pd77Ag23 Membrane) .552.5 Permeability Raw Data of a Sample B (Pd77Ag23 After 24 Hours Air Treatment) .562.6 Permeability Raw Data of a Sample C (Pd77Ag23 After 24 Hours Vacuum Annealing) .572.7 Permeability Raw Data of a Sample D (24 Hr in Vacuum Sealed Quartz Tube) .582.8 Permeability Raw Data of a Sample E (Second Run of Sample B).592.9 Hydrogen Permeability as the Function of the Surface Composition After HeatTreatment .593.1 Measured Tg , Tx And Δt of Amorphous Metals.794.1 Glass Transition Temperature Before and After Hydrogen Permeability Test .95B.1 Parts Information of the Bench-Top System .128C.1 Gaskets Information .133D.1 Gaskets and Part Information for Modification .135ix

TablePageE.1 Permeability Data of Sample A (As-Received Samples) .138E.2 Permeability Data of Sample B (24 Hr Air Treatment) .139E.3 Permeability Data of Sample C (24 Hr Vacuum Oven Treatment).140E.4 Permeability Data of Sample D (24 Hr High Vacuum Treatment) .141E.5 Permeability Data of Sample E (Second Hydrogen Permeability Test of Sample B).141F.1 Raw Data of Hydrogen Permeability of Pd-Coated Cu63Zr37.143F.2 Raw Data of Hydrogen Permeability of Non-Pd-Coated Cu63Zr37 .143F.3 Raw Permeability Data of Pd-Coated Cu46Zr54 .144F.4 Raw Permeability Data of Cu46Zr54 Uncoated.145F.5 Raw Permeability Data of Pd-Coated Cu40Zr60 .146F.6 Raw Permeability Data of Uncoated Cu40Zr60.147G.1 Raw Data of Hydrogen Permeability of Ni60Nb35Sn5 Pd-Coated AmorphousMembrane .149G.2 Raw Permeability Data of Ni60Nb35Ti5 Pd-Coated Amorphous Membranes-1 .153G.3 Raw Permeability Data of Ni60Nb35Ti5 Pd-Coated Amorphous Membranes-2 .158G.4 Raw Permeability Data of Ni60Nb35Zr5 Pd-Coated Amorphous Membranes .163x

LIST OF FIGURESFigurePage1.1 Upper Bound Correlation for H2/N2 Separation. Image Reproduced from (Robeson2008). .51.2 Prototype of a Typical Polysulfone Class. Image Reproduced from (Kesting andFritzsche 1993).61.3 Chemical Structure of MFI. Image Reproduced from (Baerlocher and Mccusker) .91.4 Schematic Drawing of CMS Pore Structures Reproduced from (Kiyono Et Al. 2010) .91.5 Schematic Showing the Process of Hydrogen Separation and Diffusion through aDense Metallic Membrane. Reproduced from (Phair and Donelson 2006). Step 1: H2Transfer to Surface; Step 2: Dissociation of H2 into Atoms; Step 3:Adsorption of HAtoms; Step 4: Diffusion of H Atoms; Step 5: Desorption of H Atoms; Step 6:Recombination of H2; Step 7: H2 Move away to Downstream. .101.6 A Hydrogen Purifier from Jonson-Matthey Company .111.7 Pd-H Phase Diagram Reproduced from the ASM Handbook .131.8 (A) TEM Image of Crystalline Materials At 5xmillion; (B) TEM Image ofAmorphous Material at 5xmillion; (C) Schematic Drawing of a Crystalline Materialwith Simple Cubic Unit Cell; (D) Schematic Drawing of Atoms in AmorphousMaterial Reproduced from (Peker 1994) .191.9 DSC Curve of a Zr54Cu46 Amorphous Metallic Membrane.211.10 Schematic Drawing of Time-Transition-Temperature Curve .22xi

FigurePage1.11 Elastic Limit and Strength of Glassy Alloys Compared to Some ConventionalStructural Materials Figure Reproduced fromHttp://www.its.Caltech.edu/ Vitreloy/Development.Html .232.1 Schematic Design of the System (1)Regulator,(2)Mass Flow Controller,(3)StopValves,(4)Pressure Sensor,(5) Back Pressure Gauge,(6)Permeation Cell,(7)MuffleFurnace,(8)Soap Bubble Flow Meter,(9)Gas Chromatography.392.2 Stainless Steel Module to Test the Hydrogen Permeability of the Free StandingMetallic Membranes. Here is a Brass Foil to Test Leak Rate. .442.3 Surface Pd/(Pd Ag) at% of all Treatment Samples Before and After HydrogenPermeability Tests. Pd/(Pd Ag) At% is Calculated from High Resolution XPSSpectra.462.4 High Resolution XPS Scanning of Pd 3d5/2, Ag 3d5/2, O 1s/Pd 3p And C 1s for allTreatment Groups After Heat Treatment and Before the Permeation Test. .492.5 Pd 3d5/2 and Ag 3d5/2 High Resolution XPS Plots After Different Air TreatmentDuration. Sample A is As-Received Sample, Sample D is Air-Treated at400 for 24 Hrs. .512.6 AFM Height Images of all Treatment Groups. Treatment Details Refer to Table 2.1.Image Size is 2 µm X 2 µm with First Order Flattening. 50 µm Height Scale fromDark to Bright. .522.7 SEM Images of all Treatment Groups at Two Scales. After 800 VacuumAnnealing (Sample D) Grain Boundaries are Exposed. .53xii